Java 通过RestHighLevelClient 使用ES的date_histogram 根据年月日做统计

/**
 * 消息趋势统计 dateType由前端传递 包括年月周
 * 按年则统计过去12个月
 * 按月则统计过去30天
 * 按周则统计过去7天
**/
public Map<String, String> msgTrendCount(String dateType) {
    //每个索引的时间field name 可能不同 根据索引设置
	String rangeField = "messageSendTime";
    //索引名
	String index = EsIndexName.TG_MESSAGE.getIndexName();
	return dateHistogram(rangeField, dateType, index);
}




private Map<String, String> dateHistogram(String rangeField, String dateType, String... indices) {
	Map<String, String> map = new HashMap<>(4);
	try {

		LocalDateTime now = LocalDateTime.now();
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd hh:mm:ss");
		String from;
		//extended bounds参数
		String boundsStart;
		String boundsEnd;
		String to = formatter.format(now);
		String format = "yyyy-MM-dd";
		//bounds的格式化类型需要和format相同
		DateTimeFormatter boundsFormatter = DateTimeFormatter.ofPattern(format);
		//间隔 年类型较为特殊
		DateHistogramInterval interval = DateHistogramInterval.DAY;
		switch (dateType) {
			case "week": {
				from = formatter.format(now.minusDays(6));
				boundsStart = boundsFormatter.format(now.minusDays(6));
				boundsEnd = boundsFormatter.format(now);
				break;
			}
			case "year": {
				from = formatter.format(now.minusMonths(11));
				format = "yyyy-MM";
				boundsFormatter = DateTimeFormatter.ofPattern(format);
				interval = DateHistogramInterval.MONTH;
				boundsStart = boundsFormatter.format(now.minusMonths(11));
				boundsEnd = boundsFormatter.format(now);
				break;
			}
			case "month":
			default: {
				from = formatter.format(now.minusDays(29));
				boundsStart = boundsFormatter.format(now.minusDays(29));
				boundsEnd = boundsFormatter.format(now);
				break;
			}
		}

		//范围查询
		BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
		boolQueryBuilder.must(QueryBuilders.rangeQuery(rangeField).from(from).to(to));
		//dateHistogram
		AggregationBuilder aggregationBuilder = AggregationBuilders.dateHistogram("dateHistogram")//自定义名称
				.dateHistogramInterval(interval)//设置间隔
				.minDocCount(0)//返回空桶
				.field(rangeField)//指定时间字段
				.format(format)//设定返回格式
				.extendedBounds(new ExtendedBounds(boundsStart, boundsEnd));//设定范围

		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
		//指定size为0 不返回文档 因为只需要数量
		searchSourceBuilder.query(boolQueryBuilder).aggregation(aggregationBuilder).size(0);

		SearchRequest searchRequest = new SearchRequest();
		searchRequest.source(searchSourceBuilder);
		searchRequest.indices(indices);
		SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
		Aggregation agg = searchResponse.getAggregations().get("dateHistogram");

		List<? extends Histogram.Bucket> buckets = ((Histogram) agg).getBuckets();
		List<String> dateList = new ArrayList<>(30);
		List<String> countList = new ArrayList<>(30);
		for (Histogram.Bucket bucket : buckets) {
			// maybe：如果不是年 则将key中的年份去掉
			dateList.add(bucket.getKeyAsString());
			countList.add(String.valueOf(bucket.getDocCount()));
		}
		map.put("chartTime", GsonUtil.getJsonStringByObject(dateList));
		map.put("chartCount", GsonUtil.getJsonStringByObject(countList));
	} catch (Exception e) {
		log.error("统计日期直方图出错：" + e.getMessage());
	}
	return map;
}